1. Field of the Invention
The invention relates generally to a liquid crystal panel, and more particularly to a reflective liquid crystal panel.
2. Description of Related Art
Recently, developments of pico projection techniques have caught the attention of many watchers, as these devices (or mini projectors) have gradually become the mainstream for the future personal digital market. As all types of electronic products are being developed towards high speed, high efficiency, light weight and compact size, pico projectors have advantages of high portability and not being limited by sites of operation. Thus in the future, pico projectors may be embedded in products such as mobile phones or digital cameras.
Generally speaking, reflective display devices are required to provide a high reflectance and contrast, as well as a fast response speed. Currently, reflective display devices include, for example, liquid crystal on silicon (LCOS) display devices or reflective display devices employing microelectromechanical systems.
When implemented in the structure of a conventional liquid crystal display (LCD), the LCOS technique can realize a substantially higher contrast and brightness. However, when the LCOS device employs nematic liquid crystal molecules, usually four issues are inherent in the device: 1) low static contrast, 2) low reflectance, 3) need of compensation films to enhance contrast, and 4) slow response speed. Typically, these four issues are correlated with each other. For example, when using compensation films to enhance contrast, reflectance is reduced. Moreover, when maintaining high contrast, a phase retardation of the liquid crystal layer needs to be increased correspondingly, and doing so increases cell gaps, thereby slowing down the response speed. Hence, imminent issues for the reflective display device include solving the aforementioned problems while achieving high image contrast and reflectance, as well as fast response time.